CITATION ANALYSIS

The neurobiology of lampreys has a literature that reaches back to the late
1800s. Much of the early work in spinal cord neurophysiology was done
in the United States by Carl Rovainen of Washington University in St. Louis
Missouri. It's difficult to pick out one particular "classic"
for the neurobiology of swimming in lamprey, as it was through a slow
accretion of information that it has become the outstanding system it has
become for understanding vertebrate locomotion. I've selected Rovainen 1974
as it is one of the earliest papers that most contemporary treatments
of the neural basis of lamprey swimming consistently cite. This paper
discusses the synaptic interactions
of Müller
and Mauthner neurons, both very important as they are some of the very few
neurons that can be individually identified in vertebrates.
Individual identification of neurons (i.e. the neuron has a size,
position, and/or other features such as color that allows the same neuron
to be located in different animals) is usually restricted to invertebrates
with their large cells, and is a property that makes cumulative studies on
the function and properties of neurons much easier.

There have been a total of 110 citations of this paper from the time of its
publication in 1974 to November 1996, for a mean rate of 5 citations per
year. The majority of articles were on aspects of the neural organization
of lamprey
spinal cord, examined with techniques of pharmacology, histology,
immunohistochemistry, and electrophysiology. A good number of these used
"fictive" swimming. This occurs in isolated spinal cord
preparations of the lamprey, and it means that the neural activity
corresponds closely to what one would see in the intact animal performing
the behavior. This is a
powerful experimental technique usually only possible with highly
stereotyped rhythmic behaviors such as locomotion, breathing, and feeding.
There were also several reviews of rhythmic behavior or locomotion.
The article has seen some dispersion beyond the confines of the
neurobiology of lampreys: one paper on the organization of the spinal cord of
the weakly electric fish, Gymnotus carapo, one on the Mauthner cells of
goldfish, one comparing dogfish and lamprey spinal mechanisms for
locomotion, one on regeneration of neuromuscular connections in the
crayfish, one on the lateral vestibular nucleus of a toadfish, and one
review on the lamprey brain from a comparative perspective. The
majority of journals of the citing papers were in neuroscience, with a
few in clinical neurology, as
the work on lamprey spinal cord is important to investigators of
the human spinal cord. Several papers on evidence of regeneration of
lamprey spinal neurons are particularly relevant to clinicians.
An interesting methodological thread was several earlier articles on the
development of isolated CNS preparations, a technique that is increasingly
common. Slightly over 30% of the 110 papers citing this paper were authored
or co-authored by Sten Grillner, a key figure in contemporary neuroscience
of locomotion as studied with the lamprey.